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I am getting an error while using SqlFunctions.SoundCode and string.Spilit() together in C# EF

I want to search using soundex() with each words of a sentence.
My C# code is:
all_data = db.SearchEntities.Where(
s => (s.EventTitlePrimaryLang
.Split(' ')
.ToArray()
.Any(d => SqlFunctions.SoundCode(d.ToString()) ==
SqlFunctions.SoundCode(srQuery.ToString())
))
)
//.AsEnumerable()
//.AsQueryable()
.ToList();
Getting this error
LINQ to Entities does not recognize the method 'System.String[]
ToArrayString'
method, and this method cannot be translated into a store expression.

Your issue is that you are attempting to filter on the split results of a property in your query. Everything in the .Where() clause off the DbSet called SearchEntities will need to be evaluated as SQL.
The error message is telling you that EF can't convert x.MyProperty.Split() into SQL.
The only alternative, which might not be desirable in this case is to have a more general filter, then perform the complex filtering in you materialised results.
db.SearchEntities.Where(s => Something general to narrow down your results)
.AsEnumerable() // materialise your results
.Where(s => s.EventTitlePrimaryLang
.Split(' ')
.Any(d => something specific with your d and sQuery))
.ToArray();

all_data = db.SearchEntities.Where(x => !string.IsNullOrWhiteSpace(x.EventTitlePrimaryLang))
.ToList();
var filteredData = all_data.Where(s => (s.EventTitlePrimaryLang.Split(' ')
.Any(d => SqlFunctions.SoundCode(d)) == SqlFunctions.SoundCode(srQuery)))
.ToList();
OR
all_data = db.SearchEntities.Where(x => !string.IsNullOrWhiteSpace(x.EventTitlePrimaryLang))
.AsEnumerable()
.Where(s => (s.EventTitlePrimaryLang.Split(' ')
.Any(d => SqlFunctions.SoundCode(d)) == SqlFunctions.SoundCode(srQuery)))
.ToList();
As Pointed out by reckface in another answer.
OR
As another alternative to the above which may or may not work, you could opt to build the query using for loops.
var results = db.SearchEntities.Where(x => !string.IsNullOrWhiteSpace(x.EventTitlePrimaryLang))
.AsQueryable();
foreach(var r in results) {
var langSplit = s.EventTitlePrimaryLang.Split(' ');
foreach(var val in langSplit) {
results = from a in results
where SqlFunctions.SoundCode(val) == SqlFunctions.SoundCode(srQuery)
select a;
}
}
return results.ToList();
The above would then filter your results bit by bit.
EDIT:
Removed The redundant .ToString() calls
EDIT 2:
Edited the code example to better help fix the problem and Identify what is wrong.
The problem is that Entity Framework cannot convert .Split(' ') into valid SQL Code. As a work around, you will need to retrieve the data first, then filter that data using LINQ
EDIT 3:
Added possibly another way to solve the issue by using .AsQueryable() to filter down the results. Thus you don't need to query the database for a large dataset and filter the results, you could get the filtered results from the db directly, assuming it dosen't build the split into the database query. I have not tested it.

LastOrDefault vs FirstOrDefault [duplicate]

In this query:
public static IEnumerable<IServerOnlineCharacter> GetUpdated()
{
var context = DataContext.GetDataContext();
return context.ServerOnlineCharacters
.OrderBy(p => p.ServerStatus.ServerDateTime)
.GroupBy(p => p.RawName)
.Select(p => p.Last());
}
I had to switch it to this for it to work
public static IEnumerable<IServerOnlineCharacter> GetUpdated()
{
var context = DataContext.GetDataContext();
return context.ServerOnlineCharacters
.OrderByDescending(p => p.ServerStatus.ServerDateTime)
.GroupBy(p => p.RawName)
.Select(p => p.FirstOrDefault());
}
I couldn't even use p.First(), to mirror the first query.
Why are there such basic limitations in what's otherwise such a robust ORM system?

That limitation comes down to the fact that eventually it has to translate that query to SQL and SQL has a SELECT TOP (in T-SQL) but not a SELECT BOTTOM (no such thing).
There is an easy way around it though, just order descending and then do a First(), which is what you did.
EDIT:
Other providers will possibly have different implementations of SELECT TOP 1, on Oracle it would probably be something more like WHERE ROWNUM = 1
EDIT:
Another less efficient alternative - I DO NOT recommend this! - is to call .ToList() on your data before .Last(), which will immediately execute the LINQ To Entities Expression that has been built up to that point, and then your .Last() will work, because at that point the .Last() is effectively executed in the context of a LINQ to Objects Expression instead. (And as you pointed out, it could bring back thousands of records and waste loads of CPU materialising objects that will never get used)
Again, I would not recommend doing this second, but it does help illustrate the difference between where and when the LINQ expression is executed.

Instead of Last(), Try this:
model.OrderByDescending(o => o.Id).FirstOrDefault();

Replace Last() by a Linq selector OrderByDescending(x => x.ID).Take(1).Single()
Something like that would be works if you prefert do it in Linq :
public static IEnumerable<IServerOnlineCharacter> GetUpdated()
{
var context = DataContext.GetDataContext();
return context.ServerOnlineCharacters.OrderBy(p => p.ServerStatus.ServerDateTime).GroupBy(p => p.RawName).Select(p => p.OrderByDescending(x => x.Id).Take(1).Single());
}

Yet another way get last element without OrderByDescending and load all entities:
dbSet
.Where(f => f.Id == dbSet.Max(f2 => f2.Id))
.FirstOrDefault();

That's because LINQ to Entities (and databases in general) does not support all the LINQ methods (see here for details: http://msdn.microsoft.com/en-us/library/bb738550.aspx)
What you need here is to order your data in such a way that the "last" record becomes "first" and then you can use FirstOrDefault. Note that databasese usually don't have such concepts as "first" and "last", it's not like the most recently inserted record will be "last" in the table.
This method can solve your problem
db.databaseTable.OrderByDescending(obj => obj.Id).FirstOrDefault();

Adding a single function AsEnumerable() before Select function worked for me.
Example:
return context.ServerOnlineCharacters
.OrderByDescending(p => p.ServerStatus.ServerDateTime)
.GroupBy(p => p.RawName).AsEnumerable()
.Select(p => p.FirstOrDefault());
Ref:
https://www.codeproject.com/Questions/1005274/LINQ-to-Entities-does-not-recognize-the-method-Sys

Entity Framework - Select single record ordered by a property

I have a table and one of the properties of the table is TotalDue.I wish to first order it by TotalDue and then select the "top" record which in this case would be the record with the highest value.
homeVM.LastSaleAmount = (from i in salesService.GetSalesOrderHeaders()
.OrderByDescending(a => a.TotalDue).First();
This is what I've tried so far but I think .First() needs a parameter and I think I need a select as well but not really sure.

You can try with Take method, is like top, but in Linq world.
homeVM.LastSaleAmount = salesService.GetSalesOrderHeaders().OrderByDescending(a => a.TotalDue).Take(1);
https://msdn.microsoft.com/en-us/library/vstudio/bb503062%28v=vs.100%29.aspx

You're mixing method syntax and query syntax, and your use of query syntax isn't necessary and making this harder. Just remove it:
homeVM.LastSaleAmount = salesService.GetSalesOrderHeaders()
.OrderByDescending(a => a.TotalDue)
.Select(a => a.TotalDue)
.First();

You are trying to put an entire entity into LastSaleAmount. use .Select(a => a.TotalDue) like:
homeVM.LastSaleAmount = salesService.GetSalesOrderHeaders()
.OrderByDescending(a => a.TotalDue).Select(a => a.TotalDue).First();

OrderByDescending with a date from another table(s)

Hopefully this question is not to confusing. Basically I'm looking for pointers on how to OrderByDecending with a date from relational tables. I have constructed a basic method that looks like it could possibly work but I'm getting errors:
DbSortClause expressions must have a type that is order comparable.
Parameter name: key
I understand what this is saying but I'm not entirely sure how to fix using Linq method syntax.
public BusinessEntities.Application GetLastUpdatedAppliction(int userID)
{
return context.tbl_User_To_Application
.Where(x => x.UserID == userID)
.OrderByDescending
(o => o.tbl_Application.tbl_ApplicationChanges
.Where(oo => oo.ApplicationID == o.ApplicationID)
.Select(s => s.ChangeDate))
.ThenByDescending(t => t.DateAdded)
.Select(y => new BusinessEntities.Application
{
ApplicationID = y.tbl_Application.ApplicationID,
ApplicationName = y.tbl_Application.ApplicationName
}).FirstOrDefault();
}
Basically I have a cross reference table that binds a user to a specific application(Website) Then inside I need to nest into two tables to get the latest changes to the Application with a "ChangesDate". So ideally this would return the last updated application. Then obviously populates my DTO.
I'm still trying to get to grips with Linq method syntax so any help would be greatly appreciated!
Regards,
Tez Wingfield

If you want to order by the last application change date:
(...)
.OrderByDescending(o =>
o.tbl_Application.tbl_ApplicationChanges
.Where(ac => ac.ApplicationID == o.ApplicationID)
.OrderByDescending(ac => ac.ChangeDate)
.First()
.Select(ac => ac.ChangeDate)
)
(...)

C# EF Deep Lambda Distinct Count Query

This is the query I am trying to do.
var commentActivity = project.ProjectDoc
.Select(c => c.Comment.Select(i => i.UserID))
.Distinct()
.Count();
What I want is the number of comments from distinct users on a specific project, but ANY ProjectDoc. This query "works" the result is just wrong. The model is like this, generically sketched.
Project
ProjectDoc
Comment
Update: I had to go one level deeper, based on the answer below I tried a few things that didn't work so I though I would post this as a reference. Note the two SelectMany methods.
var replyActivity = project.ProjectDoc
.SelectMany(c => c.Comment.SelectMany(r => r.CommentReply.Select(u => u.UserID)))
.Distinct()
.Count();

Use SelectMany instead of Select
project.ProjectDoc
.SelectMany(c => c.Comment.Select(i => i.UserID))
.Distinct()
.Count()

var data = (from con in project.ProjectDoc
select new
{
CommentCount=project.Comment.Count(x=>x.UserID==con.UserID)
}).ToList();
i think this will help you.